An increasingly sensitive environmental issue is that of preventing injury to wildlife that may occur as a result of contact with energized electrical distribution components. Modernly, electrical distribution systems rarely provided any type of electrical barrier between energized components and other objects. For instance, electrical conductors that carry electrical power from power-pole to power-pole are typically devoid of any type of insulation. In the general sense, this is quite acceptable since electrical injury typically requires a complete circuit path phase to ground or phase to phase. Hence, a small bird may land on an electrical conductor without any adverse effects. This is because the small bird contacts only one electrical conductor and the current flowing through the conductor cannot find a “path to ground”.
It is only when a living creature, including man or beast, contacts an exposed electrical conductor or other energized component and electrical current can find a path to ground that severe injury can occur. This type of unfortunate incident is more likely to occur where exposed electrical conductors are in close proximity to a grounded object or to another conductor or component that is carrying an opposite phase of a particular circuit.
In one example, a conductor, which is typically electrically isolated from a power pole by means of an insulator, can be contacted by a lineman or wildlife that has climbed the power pole. In such case, the living creature is in close enough proximity to ground by virtue of being in contact with the power pole that the slightest contact with an exposed electrical conductor or other energized component may prove fatal. Larger birds, such as raptors, are often killed when they land on or attempt to land on an exposed electrical conductor near a power-pole or on the power-pole itself. When landing on the conductor near a power-pole, a larger bird can touch the power-pole with a wing and provide a path to ground. A large bird may also short two opposite phases together. This results in a short circuit where electrical current flows through the body of the unfortunate bird from one phase to the other.
Modern electrical distribution techniques employ various types of components to affect the delivery of electrical power to residential, commercial and industrial customers. In order to effectively manage the delivery of power, one component used in today's power delivery schema is a power interruption device known as a “cutout”. Various forms of cutouts exist and most follow the general form of that described by Biller in U.S. Pat. No. 4,414,527. The modern cutout comprises an insulator that may be mounted onto a power pole or other support structure. The insulator (reference No. 14 in the referenced patent) supports an upper and lower contact assembly. The contact assemblies hold a fuse holder assembly that completes an electrical circuit between the two contact assemblies. Thus the opposing upper and lower contact assemblies form a “fuse receptacle” capable of receiving a fuse holder assembly.
Each contact assembly further comprises a conductor connector. The conductor connectors are used for connecting the cutout to a tap-point comprising the power distribution system on one end and for connecting the cutout to an electrical load. Typically, a cutout is installed between an energized electrical conductor that carries electrical power from power-pole to power-pole and a step-down transformer. In one application, a cutout is generally mounted on the power pole just below a cross-member that is used to support the inter-pole conductors. The step-down transformer, which is also usually mounted proximate to the cutout, typically receives electrical power from the electrical conductor and reduces the electrical power to a lower voltage level suitable for distribution to an end customer.
The entire cutout assembly poses a threat not only to wildlife, but also to lineworkers. This is because the upper and lower contact assemblies are not insulated. Lineworkers accept the risk of working with high-voltage electrical power as one of many occupational hazards that are encountered on the job and with foreknowledge of the hazard avoid contacting an energized cutout. Raptors and other large birds often use power-poles, their associated supporting member and components for perching and hunting. Many times, raptors and other large birds return to the power-pole with prey that they intend to consume. Because of the usual manner in which a cutout is mounted, slightly below the power-pole's cross-member, a larger bird can use the cutout as a shelf; ideal for helping manipulate their quarry during consumption. As soon as the raptor contacts the non-insulated, energized cutout assembly it can be severely injured or killed. Other animals, e.g. squirrels, can suffer the same fate as raptors and other large birds.